Quiz

2627 questions of the kind that actually get asked — in interviews, in architecture review boards, and by the person who has to run the thing at 3 AM. Every answer states the trade-off rather than the slogan, and says when the obvious choice is the wrong one.

All areas2627 Architecture Fundamentals81 Distributed Systems101 Data Architecture90 Cloud Architecture77 Networking86 API & Integration Architecture78 Reliability & Resilience88 Observability81 Performance & Capacity Engineering90 Security Architecture85 Cost Architecture & FinOps82 Business Architecture93 Architecture Communication91 Enterprise Architecture91 Legacy Modernization82 AI-Era Architecture86 Software Architecture & Engineering84 Architecture Patterns84 Architecture Decision-Making91 The Architect's Meta-Skills92 Delivery & Release Engineering93 Platform Engineering & Developer Experience92 Testing & Quality Architecture90 Data Platform Architecture88 Streaming & Real-Time Data93 Data Governance & Semantics81 Frontend & Experience Architecture91 Edge, Mobile & IoT88 Regulatory & Data Protection Architecture90 Assurance, Audit & Model Risk88

Difficulty Any beginner intermediate advanced

101 questions in Distributed Systems.

Quiz

A logistics platform ingests location updates from a large vehicle fleet every few seconds. The ingestion queue grows steadily even though workers are healthy. How do you determine the cause, and what are the possible fixes?

A telemetry ingestion queue grows continuously even though every worker reports healthy and CPU is moderate. How do you distinguish between insufficient capacity, a slow downstream dependency, oversized messages, poison messages and an incorrect workload model?

A worker's queue depth grows steadily through the day and never recovers. Adding workers helps for an hour, then it resumes. What is happening?

An IoT ingestion pipeline is falling behind. The devices cannot be slowed down. What are your options?

A multi-tenant SaaS platform is degraded for everyone because one enterprise tenant is running ten times its normal workload. What would you change so that this tenant's burst cannot affect the others?

A service calls four dependencies. How do you size its thread pools, and why is the total often smaller than people expect?

A trading platform receives a burst of market-data updates while thousands of customers submit orders. How should market-data distribution, order execution, risk checks and user-facing APIs be separated so that non-critical workloads cannot interfere with trading?

You add separate connection pools per downstream dependency for isolation. Shortly afterwards the database starts refusing connections. What happened?

You are asked to make a multi-tenant SaaS resilient to "any single failure". You propose cells. What must you find before that claim is true?

A hotel reservation platform shows ten rooms remaining while thousands of users are viewing the property. Which operations require strong consistency and which can safely use stale cached availability?

Classify DynamoDB, Spanner and Cassandra under PACELC, and say which half of the classification you would actually design around.

PACELC extends CAP with an "else" branch. Why does that branch matter more in day-to-day operation?